Biomedical subjects
Deborah A Baumgarten
Publications and source records attributed to Deborah A Baumgarten.
Renal structure in early autosomal-dominant polycystic kidney disease (ADPKD): The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) cohort.
BACKGROUND: Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by gradual renal enlargement and cyst growth prior to loss of renal function. Standard radiographic imaging has not provided the resolution and accuracy necessary to detect small changes in renal volume or to reliably measure renal cyst volumes. The Consortium for Radiologic Imaging Studies in Polycystic Kidney Disease (CRISP) is longitudinally observing ADPKD individuals using high-resolution magnetic resonance (MR) imaging to determine if change in renal and cyst volumes can be detected over a short period of time, and if they correlate with decline in renal function early in disease. METHODS: Standardization studies were conducted in phantoms and four subjects at each participating clinical center. After, in the full-scale protocol, healthy ADPKD individuals 15 to 45 years old with creatinine clearance>70 mL/min underwent standardized MR renal imaging, renal iothalamate clearance, comprehensive clinical evaluation, and determination of 24-hour urinary albumin and electrolyte excretion. Stereology was used from T1-weighted images to quantify renal volume, and region-growing thresholding was used from T2-weighted images to determine cyst volume. Renal structures were evaluated in relation to demographic, clinical, and biochemical variables using means/medians, standard deviations, and Pearson correlations. RESULTS: Reliability coefficients for MR renal and cyst volume measurements in phantoms were 99.9% and 89.2%, respectively. In the full-scale protocol, 241 ADPKD individuals (145 women and 96 men) were enrolled. Total renal, cyst, and % cyst volume were significantly greater in each decade group. Hypertensive individuals demonstrated greater renal, cyst, and % cyst volume than normotensive subjects. Age-adjusted renal (r = -0.31, P < 0.0001), cyst (r = -0.36, P < 0.0001), and % cyst volume (r = -0.35, P < 0.0001) were inversely related to glomerular filtration rate (GFR). Age-adjusted renal volume (r = 0.42, P < 0.0001), cystic (r = 0.39, P < 0.0001, and % cyst volume (r = 0.41, P < 0.0001) were related with urinary albumin excretion. CONCLUSION: MR measures of renal and cyst volume are reliable and accurate in patients with ADPKD. ADPKD is characterized by significant cystic involvement that increases with age. Structure (renal and cyst volume) and function (GFR) are inversely related and directly related with the presence of hypertension and urinary albumin excretion in individuals with normal renal function.
Incidental findings of thickening luminal gastrointestinal organs on computed tomography: an absolute indication for endoscopy.
OBJECTIVES: Incidental findings of thickened luminal GI organs (LGIO) on CT are not uncommon. However, the significance of these findings is unclear. Because of the lack of scientific data, there are no clinical guidelines for the evaluation of these radiologic abnormalities. Our objective was to determine whether endoscopic evaluation of these findings revealed significant abnormalities. METHODS: This study evaluated all incidental findings of thickened LGIO in a large medical center from October, 1997 to March, 1999 that were followed by endoscopic examinations. RESULTS: Ninety-six percent of patients with incidental findings of thickening of the sigmoid colon or rectum, 81% of patients with thickening of the distal esophagus, and 13% of patients with thickening of the cecum had significant abnormalities on further endoscopic work up. CONCLUSIONS: Although positive pathologic findings are less common in thickening of the cecum than in other LGIO, all of these incidental findings on CT warrant further endoscopic examination.
Ultrasonography in renal transplantation.
Sonography is a simple, inexpensive, and readily available imaging modality that has become an essential component of the management of renal transplantation. It is indicated in almost all patients with acute renal failure and also is useful in the evaluation of pain, infection, and hematuria and the performance of percutaneous biopsy. Although many aspects of sonography are similar in native and transplanted kidneys, there are important differences and problems unique to the renal allograft, which form the basis for this review. The anatomy of renal transplantation and changes that accompany parenchymal disorders are discussed, but particular attention focuses on problems related to the urinary tract, fluid collections, and vascular disorders. By becoming more familiar with transplant sonography, nephrologists will be better able to incorporate this indispensable tool into the care of their patients.